Liquid crystal display (LCD) dominates the flat-panel display market due to its advantages of high image quality, small size, low drive voltage, low power consumption, low impact on human eyes and the like. A conventional liquid crystal display comprises an array substrate, a color filter substrate and a liquid crystal filled between the array substrate and the color filter substrate. As shown in FIG. 1 and FIG. 2, the color filter substrate comprises a substrate 1, and a black matrix layer 2 and a color filter layer 3 provided on the substrate 1. The color filter layer 3 comprises a plurality of pixel units in a matrix form. Each pixel unit comprises a red subpixel 31, a green subpixel 32 and a blue subpixel 33, and a black matrix in the black matrix layer 2 is provided between adjacent subpixels to prevent light from leaking at a boundary between adjacent subpixels. The liquid crystal display can display various colors by modulating red light, green light and blue light, and in this way, the liquid crystal display can display a colorful image. Therefore, the color filter substrate is a key component of the liquid crystal display.
As shown in FIG. 1 and FIG. 2, the subpixels 31, 32 and 33 in the conventional color filter substrate are all designed to be rectangular and be equal in length and width. Red light, green light and blue light are different in wavelength, the subpixel corresponding to the light with longer wavelength is widened due to illusion of human eyes, and thus “chromatic aberration” occurs. That is, although the subpixels 31, 32 and 33 of three colors are designed to have the same shape and size, they have different widths on visual sense due to illusion of human eyes, to be exact, a width of the red subpixel is visually greater than a width of the green subpixel and the width of the green subpixel is visually greater than a width of the blue subpixel, thus chromatic aberration is resulted and image quality of the display device is degraded.